1. Field of the Invention
This invention relates to an apparatus for collecting and recording signals of various process values in equipments in factories, in environments of offices and hospitals, in human bodies, and the like, and to an apparatus for recording information.
2. Description of the Related Art
There has been known a detection apparatus integrated with an information recording apparatus called "data logger", which receives various analog signals, for example, temperature, pressure and sound, provided by sensors disposed at certain locations in a process plant or electronic machine system, performs A/D conversion of the analog signals, and records the resulting digital data. Data recorded in the data logger is used intact as management information or control information for the system management and quality control, or analyzed with a computer and used for the system or machine control, fault prediction, quality control, and the like.
Such a data logger is conventionally designed for each particular purpose and usage in the research and development section, manufacturing section and quality control section of various industrial fields. For example, various sensors used for a data logger need to have distinct filtering characteristics to produce sensor outputs suitable for the usage, and therefore conventional data loggers have been configured as dedicated apparatus inclusive of certain types of sensors and filters having prescribed filtering characteristics thereby to meet the requirements of individual application fields.
Thus, a conventional data logger is designed for a specific purpose, and it is virtually infeasible to use one data logger in other application fields. Data loggers have been treated as special equipment used by expert technicians, rendering an impression of remote devices to ordinary people, resulting in a limited market area. Their intricate and relatively large scale arrangement have required a proficient, handling knowledge.
Some data loggers which are small in size, light in weight, portable adapted to be set at any subject to be monitored, such as for example, a data logger L820 delivered by Unipulse Corp., in Koshigaya, Japan, which is usable in monitoring temperatures at maximum 6 points using thermocouples, and DL-100M produced by TEAC Corp., in Musashinoshi, Japan, being able to monitor temperatures at maximum 8 points and to store processed data in an IC card. Those prior art of portable loggers can be equipped with only one kind of sensors, though the sensors are exchangeable, because the programs for calculation of digital filtering and so on are fixedly stored inside the loggers and because the monitors have no means for changing programs according to any change of the sensors to be adapted to the purposes and subjects of monitoring.